1. Field of the Invention
This invention relates to an apparatus for stretching the mouth of a bag, more particularly to a stretching apparatus that can prevent unintentional closing of the mouth of a bag.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional bag 2 is shown to comprise a mouth 20, several side pockets 21, two handle straps 22, a zipper 23 provided on the mouth 20, and a stretching apparatus 3 mounted adjacent to the mouth 20. The stretching apparatus 3 includes two U-shaped frames 31 and two pivot couplers 32 which interconnect pivotally the U-shaped frames 31 in order to form a loop frame. When the U-shaped frames 31 are unfolded, the mouth 20 is stretched in an open state, as best illustrated in FIG. 1. To close the mouth 20, the U-shaped frames 31 are pivoted toward one another about the pivot couplers 31, and the zipper 23 is then sealed. Unintentional closing of the mouth 20 can occur in the conventional bag 2 because undesired pivotal movement of the U-shaped frames 32 cannot be prevented when the mouth 20 is opened.